Guideline for Thoracolumbar Pedicle Screw Placement Assisted by Orthopaedic Surgical Robot

Basic Information

• Full English Title: Guideline for Thoracolumbar Pedicle Screw Placement Assisted by Orthopaedic Surgical Robot
• Issuing Authority: Department of Spine Surgery, Beijing Key Laboratory of Robotic Orthopaedics
• Publication Date: April 26, 2019
• Published Source: Orthopaedic Surgery (Wiley Online Library)
• DOI: 10.1111/os.12453
• Target Audience: Spine surgeons, operating room nurses, surgical robot engineers and other personnel involved in robot‑assisted thoracolumbar spine surgery
• Core Objective: To standardize the workflow of robot‑assisted thoracolumbar pedicle screw instrumentation, improve screw placement accuracy and surgical safety, especially in complex scenarios with anatomical variations, minimally invasive or revision surgeries.

Core System Overview

1. Indications

1. Spinal trauma: Thoracic and lumbar burst fracture, osteoporotic vertebral compressive fracture
2. Degenerative spinal disease: Lumbar spondylolisthesis, intervertebral disc herniation, thoracic/lumbar spinal canal stenosis
3. Spinal deformity: Congenital spondyloptosis, scoliosis, kyphotic deformity
4. Spinal tumor: Primary vertebral tumor, intracanal tumor
5. Spinal infection: Tuberculosis of the spine
6. Iatrogenic thoracolumbar spinal instability

• High‑priority scenarios: Minimally invasive surgery, revision surgery, thoracolumbar deformity correction

2. Contraindications

• Severe systemic diseases intolerant to general anesthesia or major surgery (e.g., severe hemorrhagic disorders, circulatory/respiratory failure)
• Impossible to achieve satisfactory surgical patient positioning
• Patient cannot tolerate intraoperative radiation exposure
• Unable to install trackers in valid positions to ensure navigation accuracy
• Failed to obtain qualified intraoperative navigation imaging data

3. Standardized Surgical Workflow

3.1 Preoperative Preparation

1. Complete imaging evaluations: Lumbar/thoracic spine X‑ray, CT, MRI to clarify anatomical structure, lesion location and spinal cord status
2. Routine preoperative assessments: Coagulation function, cardiopulmonary function, anesthesia risk and thromboembolism risk evaluation
3. Surgical planning on robotic workstation: Determine target spinal segment, screw diameter, screw length and optimal trajectory

3.2 Intraoperative Procedures

1. Anesthesia & Positioning: General anesthesia; patient in prone position, remove fluoroscopy obstructions; prepare and expose tracker anchoring site during prepping and draping
2. Tracker Installation: Anchor patient tracker on adjacent vertebral spinous process with a clamp, tighten firmly and power on; avoid blocking optical camera or interfering with surgical operation
3. Robot Setup & Image Acquisition: Cover robot with sterile drape, install registration tool; perform intraoperative 3D image scanning (O‑arm/CBCT), system completes automatic registration and displays accuracy
4. Registration Verification: Confirm registration precision via anatomical landmarks; re‑register if accuracy is unqualified
5. Robotic Trajectory Positioning: Install screw guider, move robotic arm to target position; real‑time positioning accuracy displayed on software interface
6. Screw Placement:
   • Insert sleeve into screw guider; make mini‑incision for percutaneous MIS or expose bone surface for open surgery
   • Drill K‑wire into vertebra, confirm position via fluoroscopy
   • Implant cannulated screw directly along K‑wire; for standard screw, prepare path with cannulated tap first then insert screw
    
7. Final Verification & Closure: Verify screw position with fluoroscopy; reposition or re‑acquire images if unsatisfactory; perform reduction, rod connection and wound closure as conventional procedure

3.3 Postoperative Management

• Routine postoperative imaging (X‑ray/CT) to confirm screw position and segment alignment
• Monitor neurological function, vital signs and wound drainage; manage pain and prevent thromboembolism
• Formulate individualized immobilization and rehabilitation plan based on fixation stability and bone healing status

4. Key Precautions & Error Management

4.1 Factors Affecting Accuracy & Countermeasures

4.2 Critical Operational Rules

• Surgeons must master regional anatomy and conventional spine surgery skills, with capability to switch to traditional procedures when robot system fails
• Operating room environment must meet robot requirements (temperature, humidity, voltage, grounding); operating table should be radiolucent
• Regular maintenance of robot equipment: interface inspection, tool fatigue detection, periodic accuracy calibration
• In case of sudden power failure: Restart system; re‑acquire images and replan only if full system power off occurs